I dont see how a curved foil would add any cost over a straight foil on a new boat. Once you have a mold, its the same amount of material. I think what the current crowd is worried about is having to modify existing trunks if curved foils do become common.
Until they are proven, its still just a guess if they are faster or not.
I'm not working on curved foils, the one set I did make were for FasterDammit, and they are for the HT. I dont think I'll make any more, they are pretty labor intensive.
I dont know if I told you, but I raised the rear beam on the HT. It came out nice, and I was out last weekend in about 3-4 foot of chop and the rear beam didnt slap once. I used Forte Carbon beams and used some scrap tubes from Forte to create the riser. I'll post pics soon.
Bill